JPH087278A - Information recording / reproducing method and apparatus thereof - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a method and apparatus for controlling the length and width of a recording mark to be recorded on a recording medium with high accuracy to improve the reliability of information and the recording capacity. [Structure] A test pulse pattern generation circuit 15 and a recording pulse generation circuit 11 generate a recording pulse train, and a laser driver 10 records a recording mark on a recording medium 6. A test writing pattern detection circuit 23 based on a reproduction signal from the recording medium 5
In 2), a test writing pattern consisting of two types is detected, and the recording power when the difference (recording condition deviation signal) becomes 0 is set as the optimum recording power, and the recording power is fixed and the servo state is changed to change the recording condition. By performing a normal recording / reproducing operation with the servo state in which the deviation signal becomes maximum as the optimum servo state, the recording mark variation due to the recording sensitivity variation or the like is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording / reproducing on / from a recording medium, and more particularly to a highly accurate recording / reproducing control method for recording marks by thermal recording and highly accurate pre-recorded information. Related to the device to reproduce.

[0002]

2. Description of the Related Art A conventional recording method is disclosed in Japanese Patent Application Laid-Open No. 3-2222.
As described in Japanese Patent Publication No. 3, a recording code string of recording marks is pulsed to form a series of pulse trains corresponding to the length of the recording code train, and the length and amplitude of the pulse train are recorded immediately before the recording code train. The method is such that recording is performed by controlling according to the length of the opposite phase of the code train, dividing the pulse train into three parts, and changing the pulse width of each pulse.

[0003]

SUMMARY OF THE INVENTION The above-mentioned prior art is due to the fact that the recording sensitivity changes with respect to the recording medium due to the film thickness variation of the recording medium and the environmental temperature variation, and the variation of the light spot position control of the recording / reproducing apparatus. There is a problem in that the recording capacity cannot be reduced because the recording marks cannot be controlled with high accuracy because the relative fluctuation of the recording sensitivity is not taken into consideration. Further, the compatibility of the device with respect to the prerecorded mark is not taken into consideration, and there is a problem in that each device causes a malfunction during reproduction.

It is an object of the present invention to suppress the fluctuation of the recording mark due to the fluctuation of the recording sensitivity as much as possible and to control the recording mark with high accuracy.

Another object of the present invention is to improve the compatibility between the recording / reproducing apparatus and the recording medium and to suppress the recording sensitivity fluctuation and the recording power fluctuation due to the recording / reproducing apparatus.

Another object of the present invention is to suppress fluctuations in the light spot position control in order to prevent malfunctions during reproduction of prerecorded information due to variations among devices.

Another object of the present invention is to improve the reliability of the recording / reproducing apparatus, the storage capacity, and the information transfer rate.

[0008]

In order to achieve the above object, in order to improve compatibility between a recording medium and a recording device, a test writing is performed in advance at a predetermined position of the recording medium, and The optimum recording power and the optimum servo state are found from the obtained reproduction signal, and then the normal information recording is started.

Further, the input data bit string of the trial writing data and the normal information is set to a code string corresponding to the modulation system of the recording apparatus, and a data string for recording the code string on the recording medium is generated. Accurate recording is performed by driving a laser light source to form a recording area on a recording medium.

In order to achieve the above-mentioned other objects, a recording pulse train and a recording auxiliary pulse corresponding to a recording mark of an input data bit string of trial writing data and regular information are generated, and two lights for the recording pulse train and the recording auxiliary pulse are generated. It is recorded on a recording medium using intensity or two energy levels.

In order to achieve the above-mentioned other objects, a recording medium capable of overwriting information by modulating the light intensity of a recording pulse train and a recording auxiliary pulse is applied to a recording power and an erasing power. Is.

In order to achieve the above-mentioned other objects, trial writing is performed in advance at a predetermined position on the recording medium, and when the normal information recording is started based on the optimum recording power obtained by the trial writing, the trial writing data In addition, the input data bit string of the regular information is used as a code string of a recording device, and a data string for recording the code string on a recording medium is generated, and a laser light source is driven to form a recording area on the recording medium. In the recording waveform to be formed, the light intensity or energy level for the recording pulse train and recording auxiliary pulse corresponding to the recording mark is controlled.

Further, in order to prevent the malfunction of the prerecorded information due to the variation among the devices during the reproduction as much as possible, the fluctuation of the light spot position control is suppressed, and in order to realize the optimum reproduction state, the normal information is recorded. Prior to reproduction, a trial reading for reproduction is performed to improve compatibility between a prerecorded mark and a reproduction device.

[0014]

In order to improve the compatibility between the recording medium and the recording apparatus, the trial writing is performed in advance at a predetermined position of the recording medium, such as a variation in the thickness of the recording medium due to the exchange of the recording medium and an environmental temperature variation. Also, in order to detect a change in recording sensitivity to the recording medium due to a change in the characteristics of the recording apparatus, a strict recording mark to be recorded is written on the recording medium before recording the regular information. further,
In order to find the optimum recording power from the reproduction signal obtained from the recorded trial writing data, the recording intensity is changed and the light intensity or energy of the recording waveform is changed to execute the recording operation. In addition, the optimum recording power changes according to the change in the characteristics of the recording device, especially the position control state of the light spot. From this characteristic, the optimum position control of the light spot is realized, whereby the optimum recording condition for the recording medium can always be obtained, so that the above-mentioned recording malfunction of information due to the fluctuation of the recording sensitivity is eliminated and it is reliable. Recording and playback is possible.

Further, in order to minimize the trial writing performed immediately after recording the normal information or by recording / reproducing at a certain period, a recording pulse train and a recording auxiliary pulse corresponding to the recording mark are generated, and the recording pulse train and the recording auxiliary pulse are generated. The recording is performed by controlling the length and width of the recording mark while keeping the temperature of the recording medium substantially constant by using two light intensities or two energy levels for the pulse.

In the trial reading, the position of the light spot in the trial reading area is reproduced before the regular information is reproduced in order to prevent the reproduction malfunction due to the reproduction characteristic of each device with respect to the prerecorded information as much as possible. It is possible to improve the compatibility between prerecorded information and a device for reading the information by changing the control state and reproducing, and always realize the optimum reproduction state, and suppress malfunctions during reproduction. .

[0017]

Embodiments of the present invention will be described below. Figure 1
1 shows an embodiment of the device configuration of the present invention. An information recording / reproducing apparatus converts an optical head centered on a laser 1, a recording medium 6 for storing information, a recording processing system centered on a recording pulse generation circuit 11, and a reproduction signal obtained from the optical head into information. And a reproducing processing system centering on the reproducing circuit 20. The recording medium 6 is composed of a recording film and a substrate holding the recording film.

The controller 16 decodes the command and the information data from the upper host, decodes the command, and modulates the recorded data, and converts the coded data into a code string corresponding to the modulation method. The synthesizer 14 is an oscillator that generates a reference clock for the entire apparatus, and as a method of increasing the capacity, the ZC is used to change the reference clock for each zone to keep the recording density at the inner and outer circumferences substantially constant.
AV (Zoned Constant Angular)
When a recording method called “Velocity” is adopted, it is necessary to change the oscillation frequency of the synthesizer 14 according to the zone.

In order to improve the compatibility between the recording medium and the recording apparatus, the trial writing is performed in advance at a predetermined position of the recording medium, such as a change in the film thickness of the recording medium due to the exchange of the recording medium and an environmental temperature change. Also, an operation of writing a test writing pattern for detecting a change in recording sensitivity on the recording medium due to a change in characteristics of the recording apparatus on the recording medium before recording the regular information is performed. This trial writing pattern is converted into a code string corresponding to the modulation method, and is generated in the trial writing pattern generation circuit 15. The code string modulated according to the regular information data from the controller 16 and the code string from the trial writing pattern generation circuit 15 are input to the selector 12, and the control signal of the controller 16 corresponds to the trial writing process or the normal recording process. To switch. The code train from the selector 12 enters the recording pulse generation circuit 11 and is converted into a recording pulse train for controlling the length and width of the recording mark. These recording pulse trains are input to the laser driver 10 and the laser driver 10
The laser 1 oscillates at high output by the recording current from the prism 1, and the light emitted from the laser 1 becomes parallel light by the lens 2 and the prism 3
After passing through, the lens 4 converges on the recording medium 6 and a recording mark corresponding to the code string is recorded. The high frequency superimposing circuit 13 is provided to reduce laser noise caused by the laser 1, and during recording / erasing, the high frequency superimposing circuit may be suspended from the viewpoint of the life of the laser.

At the time of reproduction, the laser 1 is oscillated at a low output and is made incident on the recording medium 6. Further, part of the light reflected by the prism 3 enters the photodetector 8. The output signal of the photodetector 8 is amplified by the preamplifier 17 and input to the power monitoring circuit 18. In order to keep the laser power during reproduction almost constant, a control signal is input from the power monitoring circuit 18 to the laser driver 10, and the laser drive current is controlled so that the reproduction power becomes constant. The reflected light from the recording medium 6 is made incident on the photodetector 9 with its optical path separated by the prism 3. The output signal of the photodetector 9 is amplified by the preamplifier 19, and the reproduction circuit 20
To the servo circuit 24. The reproduction circuit 20 is composed of a waveform equalization circuit, an automatic gain control circuit, a binarization circuit, etc., and the inputted reproduction signal is used as a binarized signal. The binarized signal from the reproduction circuit 20 is input to a PLL (Phase Locked Loop) circuit 21 for self clocking. The reproduction clock synchronized with the binarized signal and the binarized signal obtained by the PLL 21 are input to the discrimination circuit 22 for data discrimination, and the resulting data discrimination signal is input to the controller 16 to demodulate the data. It In a magneto-optical disk device that records, reproduces, and erases information using an externally applied magnetic field, an external magnetic field generator 7 is provided, and the direction of the magnetic field is switched during recording / erasing to irradiate recording / erasing power. To do. During reproduction, the reflected light is separated into p-polarized light and s-polarized light by a wavelength plate (not shown) arranged in front of the photodetector 9 and each of them is differentiated by the photodetector (division 2) 9. A magneto-optical signal can be obtained. Further, the focus error signal and the track error signal can be obtained by the cylindrical lens (not shown) arranged in front of the photodetector 9 and the photodetector (4 divisions) 9.

During the trial writing process, the reproduced signal in the analog signal state is guided from the reproducing circuit 20 to the trial reading / test writing pattern detecting circuit 23. As the recording pattern used during the trial writing process, a combination pattern of the highest frequency closest pattern and the lowest frequency closest pattern in the device is used, and the center level of the closest pattern and the center level of the closest pattern are tested in the reproduced signal. The reading / trial writing pattern detection circuit 23 detects the difference, and the controller 16 detects the difference between the center levels. When the difference becomes 0, the recording power is determined to be the optimum recording power, and normal recording is performed. As described above, by performing trial writing, it is possible to record a highly accurate recording mark by always setting the optimum power. Further, the servo circuit 24 drives the actuator 5 based on the focus error signal and the track error signal from the preamplifier 19 to control the light spot position. In the trial writing process for optimizing the servo (focus and tracking), the controller 16 uses the servo circuit 2
The focus error signal and the track error signal of No. 4 are monitored, and while the recording power is fixed, an electric offset is applied in the focus and track directions to change the position of the light spot. The recording pattern and the detection method are
By performing the same procedure as described above and detecting the servo state in which the level difference between the densest pattern and the sparsest pattern has a maximum value, optimum light spot position control is possible.

In the trial reading process, as in the trial writing process,
The reproduced signal in the analog signal state from the reproducing circuit 20 is guided to the trial reading and trial writing pattern detecting circuit 23. In the reproduction signal (combination pattern of the densest pattern of the highest frequency and the sparsest pattern of the lowest frequency) from the trial reading area provided in advance in the recording medium 6, the center level of the closest pattern and the center level of the most sparse pattern are Detected by the trial reading and trial writing pattern detection circuit 23, the controller 16 detects the difference between the center levels, and the servo state when the difference becomes the maximum value is determined to be the optimum servo state and the normal reproduction is performed. To do.

FIG. 2 illustrates an embodiment of the recording medium of the present invention. The recording medium 6 has a read-only area (ROM area: Read Only Memory area) and a recording / reproducing area (RAM area: Random Access M).
The ROM area 30 includes a trial reading area 32, and the RAM area 31 includes a trial writing area 3.
3, 34 are provided. It is necessary to provide at least one trial writing area in the RAM area 31. By providing a plurality of trial writing areas, frequency characteristics (recording pulse rising characteristics, etc.) can be obtained.
Can be fully guaranteed.

Next, an example of the operation of the flowchart of the trial reading and trial writing processing procedure of the present invention will be described with reference to FIG. The device is operated by turning on the power supply of the device.
First, it is determined whether a recording medium is loaded in the apparatus, and if there is no recording medium, the standby state is left as it is. If the recording medium is set in the device, rotate the recording medium,
Turn on the laser. Next, a servo for controlling the light spot (autofocus: AF, tracking: T
R) is started. Since the servo follows the target point of the device (the state where the error signal is electrically suppressed), it is not always the optimum state for actual operations such as recording / reproducing / erasing. In order to confirm the compatibility between the input recording medium and the device, trial reading and trial writing operations are performed. The trial reading in the present invention optimizes the servo state of the reading device in order to accurately reproduce the prerecorded information. The pre-recorded information is applied not only to the concavo-convex signal at the time of manufacturing the recording medium but also to the case of reading the information in the RAM area as backward compatibility.

In the trial writing in the present invention, the recording sensitivity change with respect to the recording medium due to the film thickness change of the recording medium and the environmental temperature change, and the state change of the apparatus (laser emission state,
The recording power, the recording pulse, the electric offset of AF and TR, etc. are controlled so as to minimize the fluctuation of the recording mark caused by the relative recording sensitivity fluctuation due to the light spot position control status etc.), and the recording condition is changed from the reproduction signal. The deviation signal is detected and the optimum recording state is set. First, in order to determine the recording condition for the input recording medium, the recording power is sequentially changed while the servo state remains unchanged, and the primary optimum power is determined. As a result, it can be set near the final optimum power. The primary optimum power is fixed and the AF electric offset is sequentially changed for recording. During reproduction, the AF electric offset is not applied and the recording condition deviation signal is detected. When the AF is in an optimum state with the recording power fixed, the recording temperature of the recording medium is highest and the recording marks are large. By using this characteristic as a recording condition deviation signal, the optimum servo state can be determined. (If the servo status is judged to be optimal, the first
The next optimum recording power is set as the final optimum recording power, and the trial writing end signal is output. ) After realizing this optimal servo state, perform trial writing to change the recording power again,
The final optimum recording power is determined, a trial writing end signal is output, and normal operation of the apparatus (recording / reproducing / erasing of information) is started. Further, when the information cannot be accurately recorded / reproduced in the normal operation state of the apparatus, the above-mentioned trial writing is performed again and the optimum recording power is set again. If the recording medium is not replaced and the power is not cut off, only the power variable test writing for determining the final optimum recording power may be used. In addition, the test writing described above is performed when the recording medium is replaced, the power is cut off, or the like. This makes it possible to dramatically improve the compatibility of the recording medium and the device, and to improve the density and reliability of information. Although AF is described in the power fixed test writing in the present embodiment, TR can be optimized by fixing the power again and changing the TR offset after the AF is optimized. As described above, two types of servo states, that is, the servo state in the ROM area and the servo state in the RAM area are stored in the controller 16, and the servo state is changed according to each area to record / reproduce information.

FIG. 4 shows an embodiment of a recording method for recording on the recording medium of the present invention. Here, a case where a (1,7) RLL code is adopted as a modulation method will be described. The code string modulated according to the regular information data from the controller 16 described in FIG. 1 and the code string from the trial writing pattern generation circuit 15, and the output from the selector 12 is the recording code string. This recording code string is (1,7) RL
There seven different when 2T _W ~8T _W of L code, N for inverting the polarity by "1" of the modulation code for the mark edge recording
RZI (Non Return To Zero In)
signal). Here, T _W represents the window width, and the reference clock cycle oscillated by the synthesizer 14 is equal to T _W. Rotation speed of 5 inch optical disk 3000r
When recording / reproducing at pm, the recording pit length is 0.75 μm
Then, with (1,7) RLL code, the inner circumference is 2 MB / s,
A transfer rate of 4 MB / s on the outer circumference can be realized, and T _W at this time is 40 ns on the inner circumference and 20 ns on the outer circumference. The recording pulse generation circuit 11 generates a recording pulse train corresponding to the pulse portion of the recording code train. In the recording pulse train, the lengths of the first pulse and the second and subsequent pulses are different, and the first pulse has a shortest pulse width of 2T _W and 3 / 2T _W.
Pulse width and 1/2 T _W. The pulse width after 3T _W is the first pulse 3 / 2T _W and the pulse width after the second is 1
It is obtained by adding the combination of / 2T _W and the gap width 1 / 2T _W (same as the reference clock waveform). These pulses are generated in synchronization with the reference clock. This improves the control of pulse width and pulse interval.

FIG. 5 shows the recording mark shape, recording waveform and control signal. The recording waveform is composed of a combination of a recording pulse train and a gap, and a quiescent period of a time width is provided by the recording pulse train B at the trailing edges of the recording pulse trains A and C. In the recording pulse train B, by providing a gap portion having a certain time width (for example, T _W ) from the trailing edge of the recording code train, the heat from the last trailing edge of the recording pulse train causes the temperature at the leading leading edge of the next recording pulse train to rise. Try to make little changes. The laser power is set to five power levels. The reproduction power Pr during reproduction, the reproduction power Pr ′ when the reproduction power is reduced by the modulation degree to suspend the high frequency superposition during recording, the recording power due to the recording pulse train B is Pa, and the recording power due to the recording pulse train A is P.
The recording power of w1 and the recording pulse train B (the second and subsequent rear pulses) is Pw2. At the time of reproduction, the power monitoring circuit 18 monitors the fluctuation of the reproduction power and feeds it back to the laser 1 to keep the reproduction power Pr at the time of reproduction constant. The head pulse (3/2
The power of the Tw pulse) is set lower than the power of the rear pulse (1/2 Tw pulse). By doing so, the recording mark width by the head pulse and the recording mark width by the rear pulse can be made equal, and the recording mark length can be controlled with high accuracy. This is not only to make the temperature on the recording medium by the leading pulse and the temperature on the rear pulse constant, but also to make the recording mark width constant, so that the reproduction signal amplitude of the data portion obtained by reproducing the recording medium is made constant. be able to. The binarized signal can be generated by slicing directly at the center of the reproduced signal or at a certain level. Further, by using the combination of the recording pulse train and the recording auxiliary pulse, the recording power Pa by the recording pulse train B is used as the erasing power and the recording pulse train A by the overwrite-writable magneto-optical disk described in JP-A-62-175948. , C by making the powers Pw1 and Pw2 by the recording powers, overwriting can be realized.

FIG. 6 shows an embodiment of test writing pattern detection. (For (1, 7) RLL code, 2T _W) as the test writing pattern densest pattern with the highest frequency in the system the most sparse pattern is the lowest frequency (8
_Tw ) repeating pattern is used. In the case of mark edge recording, it is important to control the time axis of the recording mark, and the time axis of each pattern is controlled when the center levels of the reproduction signals of the densest pattern and the sparsest pattern are equal,
The recording power at this time is the optimum power. As described above, in this embodiment, the time base fluctuation is detected by the amplitude level fluctuation. A reproduced signal obtained by recording and reproducing the above-described test writing pattern under a certain condition is shown in FIG. In the test reading / test writing pattern detection circuit 23 of FIG. 1, the center level (V ₁ ) of the closest pattern and the center level (V ₂ ) of the most sparse pattern are detected from the reproduced signal, and the voltage difference ΔV =
Determine the V ₁ -V _2. The timing of detecting the center level V ₁ of the densest pattern is determined by the sample pulse 1, and the timing of detecting the center level V ₂ of the sparsest pattern is determined by the sample pulse 2. ΔV is input to the controller 16 as a recording condition deviation signal, and ΔV =
Find the recording condition that becomes 0. Detection examples of variable power trial writing and fixed power trial writing are shown in FIGS. 6C and 6D, respectively. In the power variable test writing detection example, the recording power is sequentially increased from P1 to P9. At the time of reproduction, ΔV corresponding to each recording power can be obtained as described above. The controller 16 determines the recording power P5 at which ΔV≈0 as the optimum recording power.
Next, an example of fixed power trial writing detection for optimizing the servo state will be described. ΔV can be detected by recording and reproducing while changing the servo state while the recording power (P5) determined by FIG. 6C is fixed. In this embodiment, the AF offset is changed from V1 to V9.
Change up to. At this time, the state where there is no electrical offset on the device is V5. Since the energy of the laser beam effectively flows into the recording medium in the state where the light spot is most narrowed down, even if the recording power is fixed, ΔV has the maximum value, so this maximum value should be judged by the controller 16. Can optimize the servo condition. In this case, the AF offset V6 is selected by the controller 16. Next, the controller 16 commands the servo circuit 24 to set the AF offset to V6, and the servo circuit 24 drives the actuator 5. In this state, the power variable test writing is performed again, the recording power is determined as described above, and the final optimum recording power is obtained. By performing such trial writing, the optimum recording power and the optimum servo state can be realized.

FIG. 7 shows an embodiment of the trial reading / trial writing pattern detection circuit 23. Here, a low-pass filter is provided for the reproduced signal from the reproducing circuit 20, the average level of the reproduced signal is detected by this, and thereafter, two sample hold circuits are used as the average levels V ₁ and V for the respective patterns. ₂ is detected, and ΔV (recording condition deviation signal) is input to the controller 16 by the differential amplifier.

FIG. 8 shows an actual measurement example of trial writing. FIG.
6A and 6B are actual measurements corresponding to FIGS. 6C and 6D, respectively. The experimental conditions are shown below.

1. Laser wavelength: 780 nm 2. Numerical aperture: 0.55 3. Recording medium: Magneto-optical disk 4. Rotation speed: 3000 rpm 5. Linear velocity: 9.4 m / s 6. Detecting window width: 40 ns Under the above conditions, the recording power was changed to
When the ΔV shown in (a) was measured, the data shown in FIG. 8 (a) was obtained. Since the power change amount of 0% was the optimum power, the power was standardized here. The recording power at this time is Pa = 3.51 mW, Pw1 = 5.51 m
It was W and Pw2 = 5.71 mW. Power change amount-2
.DELTA.V.apprxeq.0 near 0%, but this power was in a state where recording was started and was not the optimum power. When the controller 16 determines ΔV≈0, malfunction can be prevented by detecting a power value at which ΔV changes from a negative value to a positive value. Next, using the recording power (Pa = 3.51mW, Pw1 = 5.51mW, Pw2 = 5.71mW) detected in FIG.
The result of changing the offset is shown in FIG. In the device used for this experiment, Δ when the AF offset amount is 0 μm
V did not reach a maximum value, but reached a maximum value with an AF offset amount of about 0.4 μm. Therefore, the optimum state of the servo is A
It was found that the F offset amount was 0.4 μm. As a result of realizing the servo state and performing the power variable test writing again (not shown), the recording power is about 4%.
By setting it low, ΔV≈0 was achieved.

Next, FIG. 9 shows an embodiment of pattern detection by trial reading. The operation is almost similar to the test writing pattern detection described in FIG. However, the reproduction signal of FIG. 9A is a signal recorded in advance on the recording medium 6. 9B and 9C operate in the same manner as FIGS. 6B and 6D. In this embodiment, the AF offset V4 has a maximum value, and the optimum reproduction servo state can be detected.

[0033]

According to the present invention, fluctuations in recording sensitivity to a recording medium and fluctuations in recording sensitivity due to a recording / reproducing apparatus due to fluctuations in film thickness of the recording medium and environmental temperature fluctuations are suppressed, and compatibility between the recording / reproducing apparatus and the recording medium is suppressed. Since it is possible to control the recording mark with high accuracy while reducing the read malfunction due to the variation between the devices at the time of reproduction,
This has the effect of improving the reliability of the recording / reproducing apparatus, the recording capacity, and the information transfer rate.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a first embodiment of the present invention.

FIG. 2 is a perspective view of an example of a recording medium of the present invention.

FIG. 3 is a flowchart of an example of a trial writing processing procedure.

FIG. 4 is a waveform diagram of a recording code train and a recording pulse train to be used.

FIG. 5 is an explanatory diagram of recording mark shapes and recording waveforms.

FIG. 6 is a diagram of a detection example in variable power and fixed trial writing.

FIG. 7 is a block diagram of a first example of a trial writing pattern center level detection circuit.

FIG. 8 is a graph of an actual measurement example of variable power and fixed trial writing.

FIG. 9 is a diagram of a detection example in trial reading.

[Explanation of symbols]

10 ... Laser driver, 11 ... Recording pulse generation circuit, 1
5 ... Trial writing pattern generation circuit, 16 ... Controller,
20 ... Regeneration circuit, 21 ... PLL, 22 ... Discrimination circuit, 23
... trial writing pattern detection circuit, 24 ... servo circuit, 30
... ROM area, 31 ... RAM area, 32 ... Trial reading area, 33, 34 ... Trial writing area.

Claims (11)

[Claims] 1. An optimum recording power obtained by recording test write data at a predetermined position of a recording medium in order to improve compatibility between the recording medium and a recording device, and from a reproduced signal of the recorded test write data. Based on the information on the optimum servo state, the recording of regular information on the recording medium is started, and a light spot from a light source illuminates a predetermined area of the recording medium. Information is recorded by forming different recording areas, and the information recorded at a predetermined position of the recording / reproducing medium is read by trial in order to improve compatibility between the prerecorded information and the device for reproducing it. Then, in the recording / reproducing method that realizes the optimum reproducing state, the variable power test writing method in which the recording power is changed to perform the test writing, and the test writing is performed by fixing the recording power and changing the servo state. By sequentially performing the fixed power test writing method, it is possible to eliminate the fluctuation of the recording sensitivity of the recording medium and the fluctuation of the relative recording sensitivity of the recording device, and to reproduce the prerecorded information with high accuracy by the trial reading method. And a method for recording and reproducing information. 2. The information recording / reproducing method according to claim 1, wherein, in the two types of trial writing, first, variable power trial writing is performed, and second, fixed power trial writing is performed. 3. When the servo state is determined not to be optimal after the second power fixed test writing is performed, the servo state is optimized and the third power variable test writing is performed. The information recording / reproducing method according to claim 2. 4. Optical recording for recording, reproducing, or erasing using at least a laser beam and an externally applied magnetic field,
By irradiating the recording medium with a laser beam composed of discontinuous and minute pulses as a recording pulse for recording, the flow of heat diffused in the recording medium is controlled, and at least two or more power levels are selected. A method of recording and reproducing information, characterized in that the width and length of magnetic domains formed and controlled are controlled. 5. The information recording / reproducing method according to claim 4, wherein a plurality of power levels are changed substantially at the same time when the power variable test writing is performed with the at least two kinds of power levels. 6. The information according to claim 1, wherein in the power variable test writing method, the recording power is set so that a deviation signal between at least two types of specific recording patterns becomes substantially zero. Recording and playback method. 7. A servo state in which a deviation signal between at least two types of specific recording patterns is maximized is determined and set as an optimum servo state in the fixed power trial writing method. How to record and reproduce information. 8. The information recording medium according to claim 1, wherein the recording medium for implementing the trial writing and trial reading methods has at least two kinds of recording and reproducing areas, a reproduction-only area and a recording and reproducing area. Recording and playback method. 9. The information recording / reproducing method according to claim 1, wherein in the trial writing and trial reading methods, the optimum servo states in at least two types of a reproduction-only area and a recording / reproducing area can be varied. 10. In the trial reading method, at least two kinds of specific patterns are recorded in advance, and a servo state in which a deviation signal between the patterns is maximized is determined and set as an optimum servo state. Claim 1
How to record and reproduce the described information. 11. Information for recording information by irradiating a light spot on a predetermined area of a recording medium with light from a light source to form a recording area physically different from an unrecorded portion on the recording medium. In the storage device, the test writing means for recording the trial writing data at a predetermined position on the recording medium, the means for obtaining the control information of the optimum recording power and the optimum servo state from the reproduced signal of the recorded test writing data, and the control information are also included. In addition, means for starting recording of regular information on the recording medium, and trial reading of information recorded at a predetermined position of the recording / reproducing medium in order to improve compatibility of the prerecorded information and a device for reproducing the information. The test writing means has a power variable test writing method for performing test writing by changing the recording power, and a recording state is fixed to change the servo state. Means for switching the fixed power test writing method for performing trial writing by removing the recording sensitivity variation of the recording medium and the relative recording sensitivity variation due to the recording apparatus, and enhancing the information previously recorded by the trial reading method. An information recording / reproducing apparatus characterized by reproducing with accuracy.